Developer for continuous strip of photographic paper



y 1953 v. J. FORGETT 2,644,384

DEVELQPER FOR CONTINUOUS STRIP OF PHOTQGRAPHIC PAPER Original Filed July24, 1947 4 Sheets-Sheet l BY MN M ATTORNE Y.

O y 7, 1953 v. J. FORGETT 2,644,384

DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIO PAPER A 7 TORNEYS July 7,53 v. J. FORGETT 6 8 DEVELOPER FOR commons STRIP 0F PHOTOGRAPHIC PAPEROriginal Filed July 24, 1947 4 Sheets-Sheet 3 i; :Ej

INVENTOR.

\xxwx WM ATTORNEYJ J 7, 1953 v. J. FORGETT 2,644,384

DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIC PAPER Original Filed July24. 1947 4 Sheets-Sheet 4 FIG.9

INVENTGR. QM X QQ ATTORNEYJ Patented July 7, 1953 UNITED STATES ATENTOFFICE DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIC PAPER Valmore J.Forgett, Ridgefield, N. .L, assignor to Sweco Products, Inc., RidgefieldPark, N. J., a corporation of New Jersey 2 Claims.

This invention relates to apparatus for developing, fixing and washingstrips of photographic paper.

Substantial economies can be effected in the commercial printing ofphotographs by using long strips of photographic paper for printinggroups of negatives, and then processing all of the prints in acontinuous operation. When completed and dried, the separate prints areout apart and sorted. The apparatus of this invention is a developer, itbeing understood that a developer includes means for fixing and washingthe strip immediately after its development. One object of the inventionis to provide an improved developer with guide rollers for reversing therun of the strip as it passes through and between successive tanks ofliquid, and to maintain some tension on the strip between successiveguide rollers regardless of stretching of the paper while wet.

Another object of the invention is to provide a continuous stripdeveloper with simple and compact power mechanism for driving successiveguide rollers and wind-up reels, and with provision for accommodatingthe speed of a windup reel to the diameter of the strip that is alreadywrapped around the reel.

Some features of the invention relate to the automatic control of thetemperature of the developer, and to coordination of the developertemperature with the speed of the strip and the extent of the tanksthrough which the strip passes for fixing and washing.

Other features of the invention relate to the construction of the frameof the apparatus. In

the preferred construction, this frame is fabricated from structuralsections which hold a row of tanks in assembled relation. The frameincludes longitudinal structural elements along opposite sides of therow of tanks, and transverse elements connected with the sides of theframe, but extending beyond the sides of the frame to provide supportsfor certain parts of the apparatus which must be located outside of thetanks. Still other features relate to the liquid circulating system ofthe apparatus for maintaining the liquids in the respective tanks incondition for effective and efficient operation, and for maintaining acirculation of water through the washing tanks.

This application is a division of my copend" ing application Serial No.763,411, filed July 24, 1947, now Patent Number 2,461,419 issued onFebruary 8, 1949.

Other objects, features and advantages of the invention will appear orbe pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like referencecharacters indicate corresponding parts in all the views,

Figure 1 is a side view partly broken away, showing developer apparatusembodying this invention,

Figure 2 is an enlarged top plan view of a portion of the apparatusshown in Figure 1,

Figure 3 is a sectional view taken on the line 33 of Figure 4,

Figure 4 is a vertical sectional view through the first two tanks andpart of the third tank of the apparatus shown in Figure l, the sectionbeing taken on a plane parallel to the plane of the drawing in Figure 1,

Figure 5 is an enlarged sectional view-taken on the line 5-5 of Figure4,

Figure 6 is a greatly enlarged perspective view of one of the clips anddrain plates shown in Figure 4,

Figure 7 is an enlarged fragmentary, Vertical elevation of the upperportion of the apparatus shown in Figure 1, but viewing the apparatusfrom the opposite side,

Figure 8 is an end view of the apparatus shown in Figure 1,

Figure 9 is a view similar to Figure 2, but showing the discharge end ofthe developer apparatus.

The apparatus shown in Figure 1 comprises a fabricated frame Ill made upof vertical sections l I connected together by longitudinally extendingsections l2 and transverse sections 13. Within this frame there aretanks comprising a developer tank !5, three tanks It for fixingsolution, and five tanks ll for water.

The paper strip to be developed is wrapped in a reel 20 and supportedfrom brackets 2i at one end of the frame Ill. The strip, indicated bythe reference character 23, unwinds progressively from the reel 20,passes over a first guide roller and then downward into the developertank l5.

Within the developer tank l5, at a predetermined distance irom thebottom of the tank, there is an idler guide roller which is not shown inFigure l, but will be described in connection with subsequent figures ofthe drawing. The strip 23 passes around the idler roller in thedeveloper tank l5 and thence upward to another guide roller 21. Thissecond guide roller 21 again reverses the run of the strip so that itpasses downward into the first one of the tanks it. This first tank Itcontains a quick fix solution, that is, a chemical solution that willarrest instantly the action of any developer remaining on the paper.

The strip 23 travels around other rollers which cause it to passdownward to a predetermined depth in each tank and then upward aroundother guide rollers and downward into successive tanks. The second andthird tanks [6 are filled with solution for effecting a permanent fixingof the photographs, and the next five tanks I! are filled with water forthoroughly washing the strip before it passes over a final guide roller29. From this final guide roller 29, the strip 23 is wound up on a reel30, supported from the frame ill by brackets 3|, and driven by powermechanism which will be described in connection with the other views.

Figure 2 shows the roller 25 and its axle 34 supported in bearing blocks36 and 31. These bearing blocks are supported on the uppermostlongitudinally extending frame sections !2 of the apparatus. The roller25 is of substantially the same width, or slightly wider than thetransverse width of the paper strip with which the developer is intendedto be used. The transverse width of the tank 15 is greater than thewidth of the roller 25. The bearing blocks 36 and 3! are connected totheir respective supports H! by screws 45.

The axle 34 extends through and beyond the bearing block 35 and is heldagainst endwise movement by a thrust collar M on one side of the bearingblock 35 and by the hub of a sprocket 48 on the other side of thebearing block 35. The thrust collar 41 and sprocket 48 are preferablypinned to the axle 34 so as to turn as units with the axle.

Between the tank 15 and the first one of the tanks l there is anotherguide roller 2! with an axle 5| supported by hearing blocks 35 and El.There is a thrust collar 41 and a sprocket 48 attached to the axle 5!,the construction being identical with that of the axle 34. Between allof the successive tanks of the developer there are similar guide rollers50.

Midway between the guide rollers 25 and 21 there is a frame 54 with abar 55 at its upper end. This bar 55 is considerably wider than theremainder of the frame 54, and its opposite ends serve as hangers forsupporting the frame 54 from the adjacent longitudinal frame sectionsi2. Open top sockets 51 are provided in the frame sections I?! forreceiving the ends of the bar 55, and there are other frames 54extending downward into the tanks between all of the subsequent guiderollers of the apparatus.

The frames 54 support idler guide rollers 60 (Figures 4 and 5) near thelower ends of the tanks. These idler guide rollers 60 have flanges 5!for preventing transverse movement of the strip. The advantage of theseflanges is that they prevent the strip from becoming displaced on theidler guide roller 60 during the initial threading of the strip, or aleader, through the apparatus.

In the construction illustrated, each of the frames 54 includesvertically extending side channels 52 connected at their upper ends byhe bar 55 and connected midway between their ends by tie bolts 63. Whenthreading the strip or leader, the frames 54 are lifted out of thetanks, the strip or leader is extended across between the guide rollersat opposite ends of the tank, and the roller 60 is placed in contactwith 4 the top surface of the strip and pushed downward into the tankuntil the bar 55 at the top of the frame 54 enters into the supportingsockets 5'! which hold the frame 54 in working position. The strip 23 isthen located in the tank in the position indicated in Figure 4.

The angle which the downwardly extending run of the strip makes with theupwardly extending run depends upon the depth and the length of therespective tanks. In the water tanks, which are not as wide as thedeveloper and fixing solution tanks, the strip extends downwardly andupwardly at steeper angles. In describing the operation of the guiderollers for reversing the run of the strip, it will be understood thatthis expression does not denote a change in direction which must amountto but means merely that the direction of the strip is changed by anangle greater than The actual value of the angle depends uponcorrelations of horizontal and vertical distances between the guiderollers.

Deep tanks have the advantage of reducing the length of the apparatusand locating the guide rollers and the winding and unwinding reels atconvenient heights for handling by an attendant when the apparatus isstanding on the floor. The deep tanks have the further advanta e that alonger length of strip is immersed at the same time and the strip cantherefore travel faster and still have each unit of area immersed for aperiod suiiiciently long for the desired treatment by the liquid in thetank.

The developer and fixing solution tanks are made longer longitudinallythan the water tanks because the strength of the chemicals is affectedby their reaction with the emulsion on the paper, and a substantialvolume of chemical causes the change in strength to take place moreslowly. Water is circulated continuously through the water tanks; and ifsufiicient provision is made for circulating and replenishing thedeveloper and fixing solutions, the tanks for those solutions need notbe any larger than the water tanks.

In the preferred construction of the apparatus, each of the tanks has aninlet pipe 64 (Fig. 3) opening into the tank near the lower end of thetank. Each inlet pipe 64 has an upwardly extending portion that rises toa level above the liquid level in the tank, and that connects with asource of supply of the kind of liquid used in the particular tank withwhich that inlet pipe connects. A supply pipe 66 leading to the liquidsupply source connects with the upper end of the inlet pipe 64. Near theupper end of each tank there is a drain comprising an overflow pipe 68opening through the side of the tank at the intended level of the liquidin the tank. This liquid level is indicated in Figure 3 by the dottedline 75. Each of the overflow pipes 68 opens into a common drain pipe l2(Fig. 1) that rests on extensions of one of the transverse framesections 13. This drain pipe 12 is held in place on the frame by U-bolts"l5, and it has an outlet 16 near its lower end leading to the sewer.

The inlet pipe 64 leadin to the developer tank I5 is supplied withdeveloper from a reservoir. The developer runs into the pipe 64 at arelatively slow rate, but suflicient to maintain the required strengthof the developer in the tank. Similarly, fixing solution for the quickfix in the first of the tanks I6 is supplied from a reservoir to thepipe 64 that leads to the first of the fixing solution tanks 16.Similarly the other tanks 16 are supplied with fixing solution and atrates to maintain the strength of the chemicals in the fixing tanks.Water for the final tanks is similarly supplied to the bottoms of thetanks through pipes 64 and from a watersupply line that connects withall of the water tank inlets and at a rate fast enough to maintain thenecessary purity of the washing water.

Contamination of the liquid in one tank by liquid carried on the stripfrom the previous tank is prevented by drain plates 80 (Figs. 4 and 6).Each of these drain plates is attached to a clip having a center portion82 that bridges the upper ends of the adjacent sides of successivetanks, and has downwardly extending portions 83 that extend along theinside walls of the successive tanks for a limited distance to hold theclips in place. Each drain plate 80 is attached to its clip in aposition that gives the drain plate a substantial slope when the clip isin position on the upper edge portions of the tank Walls. These clipsare placed on the tanks in such a direction that the drain plates 80slope toward the tank from which the paper stri is emerging as itapproaches the guide roll above the drain plate.

The guide rollers 2'! are far enough above the liquid. levels in thetanks to permit a substantial portion of the liquid on the paper to runback into the tank from which the paper emerges.

What liquid is squeezed off onto the guide rollers 2'5 by contact of thestrip with the guide roller drips from the bottom of the guide rolleronto the drain plate 89 from which the liquid runs back into the tankfrom which it came.

In order to obtain uniform results, the apparatus controls both thetemperature of the liquid in the developer tank and the length of timethat the paper is exposed to the action of the developer. Thetemperature control is obtained by supplying a tortuous run ofrefrigeration tubing 81' (Figs. 3 and 4) below the level of the liquidin the developer tank I5. Heat insulation is provided around the tankI5. This insulation includes panels 89 covering both the front and backof the tank i5, and other panels 88 that cover the sides of the tank.The side panels 88' preferably extend for substantially the full lengthof the apparatus to cover all of thetanks and give the equipment aneater appearance. The ends of the tubing 81 extend through openings ina side wall of the tank I5, near the bottom of the tank, and this tubingis connected with a refrigeration unit 89 (Fig. 8).

Additional refrigerant is supplied by the unit 89 to the refrigerationtubing 81 wheneve the temperautre of the liquid in the tank I5 exceeds apredetermined limit. This automatic temperature control can be effectedby means of a thermostat, but is preferably obtained by using thepressure variation with change of temperature to start and stop therefrigeration unit in accordance with the practice commonly employed fordomestic refrigerators.

The length of time that the paper strip is exposed to the action of thedeveloper depends upon the speed of rotation of the guide rollers. Therollers 25 and 2'! are driven by a sprocket chain 9! (Fig. 7). Thischain, which extends across all of the sprockets 48 on the near side ofthe apparatus in Figure '7, is driven by a sprocket 92 on the low speedshaft of a gear reduction unit 93. A pulley 94 on the high speed shaftof the gear reduction unit is rotated by a V-belt 95 from a variablespeed pulley mechanism 95.

Power is supplied to the'variable speed pulley mechanism 96 from anelectric motor 91 and through a V-belt 98. The gear reduction unit 93,the variable speed pulley mechanism 96 and the motor 91 are allconnected to and supported by a" shelf or platform I00 that rests upontransverse frame sections I3 extending from one side of the apparatusbeyond the vertical sections II, as most clearly shown in Figure 8. Thevariable speed pulley mechanism 96 includes two pulleys IOI and I02carried on an axle I03. This axle I03 is supported by a frame that isconnected by a pivot I05 with supports I06 that are attached to theplatform I00.

The pulleys WI and I02 have their adjacent faces on opposite sides of acommon center flange which is movable within a limited range toward andfrom the other flanges of these pulleys to vary the width of the groovesof the respective pulleys, and to thus increase or decrease theeffective diameter of the pulley faces on which the V-belts and 98 (Fig.'7) run. For example, if the frame supporting the axle I03 is moved tothe right about the pivot I05 in Figure 7, the tension of the belt 98 isincreased, and that of the other belt 95 is decreased. This causes theV-belt 98 to be forced more deeply into the groove of one of thepulleys, widening the groove and forcing the intermediate flange, thatis common to both pulleys, to move toward the other belt 95 so that theother belt with the relaxed tension rides higher in the narrowed grooveof the pulley I02. This adjustment causes the motor 91 to drive thesprocket 94 at higher speed.

The pivots I05 are provided with sufiicient friction, or other means areused, for holding the frame that supports the axle I93 in its variousadjusted positions. By means of this speed control very accurateadjustment can be obtained for the speed of rotation of the guiderollers, and the length of time that the paper is exposed to the actionof the developer is accurately regulated.

The guide rollers 25 and 21 over which the strips pass are preferablycrowned in order to keep the strips centered on the guide rollers as thestrips pass through the machine. The idler rollers 60 may also becrowned or the flanges BI can be relied upon to keep the strips centeredon these guide rollers 50.

The driven guide rollers 25 and 21 are preferably of progressivelylarger diameter between successive tanks. Since the rotary speed of allof these guide rollers is the same, in the construction illustrated, thelarger diameter gives the successive guide rollers progressively higherperipheral speeds to compensate for stretch in the paper strip and tomaintain some tension on the strip within the tanks. The faces of theseguide rollers are preferably rubber and smooth enough to allow someslipping of the rollers on the paper before the tension becomes greatenough to tear the paper. Some tension is important because any play orsagging of the strip in the tanks would be cumulative and might resultin rubbing and scratching of the paper on stationary portions of theapparatus. Other means can be provided for obtaining the progressivelyhigher peripheral speed from the guide roller to the next.

Beyond the last guide rollers 29 (Fig. 9) there are centers I23 forholding the reel 30 on which the developed paper strip is wound. One ofthe centers I23 is preferably fixed and rigidly secured to theright-hand bracket 3| extending from the fixed frame of the apparatus.The

other center I23 is attached to the inner end of a shaft I28 thatrotates in a bearing I 29. This shaft I28 is movable longitudinally inthe bearing I 29 against the pressure of a spring I39. The bearing I29is fixed to the adjacent bracket 3| extending from the fixed frame ofthe apparatus, and the spring I30 is compressed between this bracket 3|and a flange I34 attached to the end of the shaft adjacent the centerI23.

A pin I35 fits into a recess in the reel 39 to transmit rotary motion ofthe shaft I28 to the reel. In order to turn the reel 30 at differentspeeds in accordance with the diameter of the paper strip wound on thereel at any given time, a friction drive is provided for rotating theshaft I28. This friction drive comprises a coil spring belt I 38 whichpasses over a pulley I39 on one end of the shaft I28, and another pulleyI40 on the same shaft with the guide roller 29.

With the pulleys I39 and I40 of the same diameter, the rotary speed ofthe shaft I28 is equal to that of the guide roller 29. The reel 30 ismade with a diameter not less than that of the final guide roller 29 sothat the length of the paper strip wound on the reel 30, with eachrevosution of the reel, is equalto the length of the strip that comesfrom the apparatus over the drivenv guide roller 29. As the diameter ofthe strip wound on the reel 39 increases, the rotary speed of the reelmust decrease. This is possible without imposing excessive tension onthe strip because the spring belt I38 can slip easily on the pulleys I39and I49. The tension of the spring belt I 38 is chosen so as to supplyjust enough friction to cause the paper strip 23 to wrap up on the reel39 with the desired pressure between the successive convolutions.

The preferred embodiment of the invention has been illustrated anddescribed, but changes and modifications can be made and some feature ofthe invention can be used alone, or in different combinations withoutdeparting from the invention as defined in the claims.

I claim as my invention:

1. In a developer for paper strips including a plurality of tanks forliquids that are used to develop, fix and wash the strip, thecombination with said tanks of rollers over which the strip passes intraveling successively through the liquids in the different tanks, saidrollers including a roller within each tank in position to reverse therun of the strip in the tank, other rollers located between the tanks inposition to reverse the run of the strip between successive tanks, saidother rollers between successive tanks being of progressively largerdiameter toward the strip discharge end of the developer to compensatefor increased length caused by stretching of the strip while wet, andsaid other rollers having smooth peripheral surfaces that slip on thesurface of the wet paper when the paper tension reaches a predeterminedvalue, which value is substantially less than the tension required totear the paper, common power driving means, and mechanism through whichthe common power driving means rotates said other rollers at equalangular speeds.

2. Apparatus for developing, fixing and washing long strips ofphotographic paper in a continuous operation, said apparatus including aseries of tanks through which the strip passes, a roller between eachtank and the next for changing the direction of the run of the strip,each roller having a smooth peripheral surface that slips on the surfaceof the wet paper when the paper tension reaches a predetermined value,which value is substantially less than the tension required to tear thepaper, an idler roller located down in each of the tanks and aroundwhich the strip passes to reverse its run in the tank, and common powermeans connected with the rollers between the successive tanks anddriving said rollers at successively greater peripheral speeds tomaintain some tension on the strip passing to and from the idler rolls.

VALMORE J. FORGETT.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 525,849 Mackusick Sept. 11, 1894 1,141,484 Javault June 1,1915 1,567,051 Thompson June 1, 1926 1,967,889 Kitroser July 24, 19342,248,333 Burbank July 8, 1941 2,346,530 Wyllie, Jr. Apr. 11, 19442,461,419 Forgett Feb. 8, 1949

